1. Technical Field
The present invention relates to a two-axis gyro module.
2. Related Art
Related art gyro sensors have been formed such that sensors including one detection axis each are combined so as to perform a multi-axis detection. For example, a multi-axial semiconductor sensor disclosed in JP-A-2003-28646 is formed such that three sensor blocks to which semiconductor sensors capable of performing one-axis detection (angular velocity sensors or acceleration sensors) are respectively attached are joined to each other and fixed. Further, a multi-axis detecting vibration gyro disclosed in JP-A-7-306047 includes a plurality of planar substrates provided with a vibration gyro and a signal processing circuit, and has a shape of a quadrangular prism or a rectangular column formed by standing the planar substrates with respect to one of the plurality of planar substrates so as to detect rotation angular velocities in multi-axial directions.
The above gyro sensor performing the multi-axial detection mounts a sensor element having a detection axis for one-axis, so that in a case of performing a two-axial detection, for example, one sensor element has to be stood perpendicular to the other sensor. In this case, the gyro sensor has an approximate L-shape from a lateral view, so that the gyro sensor can not be made low-profile and it produces a useless space in a module. Namely, in the gyro sensor performing the two-axis detection (Z-axis detection and Y-axis detection), the detection axis that the gyro sensor needs has to be matched with the detection axis of the sensor element. Therefore, the detection axis of the sensor element for the Z-axis detection needs to be perpendicular to the detection axis of the sensor element for the Y-axial detection. Thus the height of the gyro sensor depends on the width of a main surface of the sensor element that is stood. Therefore, even if a thin sensor element is used, the gyro sensor can not be sufficiently miniaturized.
Further, in the related art gyro sensors performing the multi-axial detection, one of sensor elements mounted thereon has been used for one-axis detection. Namely, each of the sensor elements detects an angular velocity at each detection axis. Therefore, in terms of an output of the gyro sensor, an output of one detection axis is an output of one sensor element. In addition, even if a signal outputted from the sensor element includes noise, the signal is used as it is in the following process. Therefore, if the signal level is increased, the noise is also increased. Further, if a filter and the like are provided so as to remove the noise, the circuit becomes large.